The Structural and Optical Properties of Polyvinyl Pyrrolidone-doped with Zinc Selenide

This study describes a method for solution casting of polyvinyl pyrrolidone (PVP) reinforced with 0 wt.%, 1 wt.%, 3 wt.%, and 5 wt.% zinc selenide (ZnSe). After production, scanning electron microscopy (SEM) was used to examine the nanocomposite surfaces, and thus confirmed the constant dispersion of ZnSe nanoparticles (NPs) within PVP. Subsequent Fourier transformation infrared spectroscopy (FTIR) analysis showed that the ZnSe NPs and PVP matrix interacted physically. Analysis of the optical properties of PVP–ZnSe nanocomposites showed that increased ZnSe NPs concentration in the PVP solution increased absorbance and decreased transmittance. Further integration of ZnSe NPs at a concentration of 6 wt.% within the PVP–ZnSe nanocomposite resulted in a decrease in the energy gap. Specifically, we observed a decrease in the energy gap from 4 to 3.1 eV for the allowed indirect transition and from 3.94 to 2.9 eV for the forbidden indirect transition. Overall, the weight percentage of ZnSe NPs demonstrates a direct relationship with their absorption factor, extinction factor, index of refraction, real and imaginary components of dielectric constants, and optical conductivity. These results indicate that PVP–ZnSe nanocomposites possess exceptional optical capabilities, and may be suitable for use in photodetector applications, especially as ultraviolet (UV) detectors.